The call to triple-0 came just after 7am yesterday.
On the end of the phone, Carlos Lopez was frantic. His family was dying. He needed help.
But when officers from Fairfield Local Area Command arrived, they found an agitated 44-year-old, his own stab wounds a clue to what officers would shortly find.
Still brandishing a knife, the man was so agitated that police officers first on the gruesome scene were forced to draw weapons and fire a single Taser shot, rendering the man helpless.
He was taken away for treatment. But the horror of five dead bodies - two of them the resident's pet chihuahuas - lay in a room nearby.
There in the St John's Park home, near Fairfield, police discovered the bodies of the man's parents and brother, killed in an apparent triple-murder and suicide attempt.
Police sources yesterday told Fairfax the victims were Lopez's mother, father and another son. But they have a different surname to him.
Police found all three victims inside the unit's master bedroom. Two were on the bed, the third on the floor, the son possibly having come to his parents' rescue.
Two dogs were also found stabbed to death, with police saying the home was a confronting sight, with so much blood at the scene.
Officers were last night being counselled, and completing their own statements about the events.
Fairfield Superintendent Peter Lennon said police were unaware of any problems at that address. ''We haven't got any motive,'' he said. ''The people living at this address are not known to us.''
Fairfield detectives, with the assistance of State Crime Command's Homicide Squad, were last night expected to charge the man in custody.